Integrating Elvis 5 in Enterprise Server 10 on AWS - Load balancer information

When integrating Elvis 5 with Enterprise Server 10 in an Amazon AWS environment, load balancers can optionally be used.

Various ways of doing this exist. To help in setting up the environment, this article provides information to determine the following:

• If Sticky Sessions should be enabled
• If the AWS Elastic Load Balancer (ELB) and/or the AWS Application Load Balancer (ALB) are supported

Note: Looking for similar information for Elvis 6? See: Integrating Elvis 6 in Enterprise Server 10 on AWS - Load balancer information.

Before you start

The information in this article can only be used when all of the following applies to your environment:

1. Elvis Server and Enterprise Server are set up in Amazon Web Services (AWS).
2. Elvis and Enterprise both have a load balancer set up; either the Elastic Load Balancer or the Application Load Balancer.
3. The Elvis Server setup consists of multiple nodes.
4. The Enterprise Server setup consists of multiple Application Servers that are connected to one database.

Summary

The following table shows a summary of this information. For more details, see the sections below.

Feature	Elvis load balancer	Enterprise load balancer
Sticky Sessions	Enabled	Enabled
ELB and ALB support	ELB only	ALB and ELB

Sticky Sessions

Sticky Sessions should be enabled for the Elvis load balancer as well as for the Enterprise load balancer.

Background information

• Elvis 5 works with session IDs. The session created by one node is unknown to another node. Once logged in, succeeding calls have to arrive at the very same node. This is achieved by using Sticky Sessions.

• Enterprise Server: The acting Smart Connection or Content Station user is logged on to Elvis by Enterprise Server (if the user is unknown to Elvis, a configured fallback user is used).

The token/session is stored in a cookie jar that travels over the back-end connection between one particular Application Server of Enterprise and the Elvis load balancer.

If the next request from Smart Connection or Content Station would arrive on a different Application Server of Enterprise, the cookie jar would not be found and it would therefore log on to Elvis again. This would be very inefficient. Using Sticky Sessions resolves this.

ELB and ALB support

For the Elvis load balancer, use ELB.

For the Enterprise load balancer, use ALB or ELB.

Background information

• Elvis load balancer: Although Enterprise Server accepts simultaneous Content Station requests over multiple Application Servers, this seems to confuse ALB in its session registrations using cookies. ALB is therefore not supported for the Elvis load balancer.